DC1738A Analog Devices

DEMO MANUAL DC1738A LTM8028 36V , UltraFast, Low Output IN Noise, 5A Module Regulator Description Demonstration circuit 1738A features the LTM 8028, a voltage. The SENSEP pin creates a Kelvin sense connec- Module step-down converter that integrates both a high tion to account for voltage drops due to PCB resistances efficiency switching regulator and a 5A UltraFast linear between the regulator and the load. regulator, resulting in a low noise solution suitable for high The LTM8028 data sheet gives a complete description of speed data applications. The demo circuit is designed for the part, operation and application information. The data an input voltage of 6V to 36V and an operating frequency sheet must be read in conjunction with this demo manual of 250kHz. The output voltage is digitally programmable prior to working on or modifying DC1738A. from 0.8V to 1.8V in 50mV increments by adjusting the Design files for this circuit board are available at three tri-state inputs VO0, VO1, and VO2. DEMO MANUAL DC1738A p s Specifications are at T = 25C A PARAMETER CONDITIONS MIN TYP MAX UNITS Input Voltage Range V = 0.8V to 1.8V 6 36 V OUT Output Voltage* Default Setting 1.773 1.8 1.827 V Maximum Output Current 5 A Switching Frequency R = 165k 250 kHz T *For other output voltage settings, refer to Table 1 Table 1: VO2 to VO0 Setting vs Nominal Output Voltage 0 V = 12V VO2 VO1 VO0 V IN OUT(NOM) V = 1.5V OUT 20 Low Low Low 0.80V I = 5A OUT Low Low Float 0.85V 40 Low Low High 0.90V 60 Low Float Low 0.95V 80 Low Float Float 1.00V Low Float High 1.05V 100 Low High Low 1.10V 120 Low High Float 1.15V 140 Low High High 1.20V 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 FREQUENCY (MHz) Float Low Low 1.25V dc1738a F01 Float Low Float 1.30V Float Low High 1.35V Figure 1. DC1738A Output Noise Spectrum Float Float Low 1.40V Float Float Float 1.45V Float Float High 1.50V Float High Low 1.55V Float High Float 1.60V Float High High 1.65V High Don t Care Low 1.70V High Don t Care Float 1.75V High Don t Care High 1.80V dc1738af 2 INTENSITY (dBm) ummary erformance